Recently, the interest of consumers in health with foods has been quite increasing. For this reason, natural foods and functional foods have been popular. Among these, soy milk made from soybeans contains good quality protein and plant linoleic acid, and also contains plenty of nutrients such as vitamin E and lecithin. Hence, the amount of soy milk consumed in the form of functional food as a gift by nature is increasing year after year. Moreover, isoflavone, a component of soybean, has attracted attention because isoflavone has various physiological functions such as preventing osteoporosis, relieving menopausal disorders, and preventing arteriosclerosis.
Accordingly, numerous researches have been conducted heretofore on soy milk and the method for producing soy milk. Nevertheless, it is hardly said that soy milk is a beverage acceptable to anybody due to soybean odor, raw smell, astringency, and so forth peculiar to soybeans, which are generated in steps of grinding and extracting soybeans. The main cause of soybean odor and raw smell peculiar to soybeans is thought to be an action of lipoxygenase. To suppress this action, there have been such proposals as a production method in which grinding is performed under high temperature condition or under oxygen free condition, a production method in which lipoxygenase deficient soybeans are utilized, and other methods. However, none of these methods is said to be simple.
On the other hand, numerous researches have also been conducted to suppress soybean odor, raw smell, and astringency peculiar to soybeans by simply utilizing food additives. For example, Patent Literature 1 proposes a technique of adding whey protein to reduce the raw smell and astringency peculiar to soybeans, so that a soybean food is obtained which is easy to eat and has a favorable flavor. Moreover, Patent Literature 2 proposes a technique of adding palatinose to reduce unpleasant taste and odor derived from soybeans, so that soy milk is obtained which is excellent in light taste and aftertaste. Further, Patent Literature 3 proposes a technique of adding sugar phosphate derived from potato to reduce or improve the taste, the smell such as bitterness, astringency, and raw smell, and so forth, so that the usage and nutritional value of foods are expanded.
However, it cannot be said that sufficiently satisfactory results have been obtained. A technique has been demanded to more simply suppress soybean odor, raw smell, and astringency peculiar to soybeans.
Meanwhile, a medium-chain fatty acid and/or a triglyceride containing a medium-chain fatty acid are quickly absorbed, when taken into a body, and shortly thereafter burned in the liver to produce energy. Based on this tendency, for example, Patent Literature 4 proposes a food and a drink containing such medium-chain fatty acid and/or triglyceride containing a medium-chain fatty acid. Nevertheless, there is almost no report on soy milk containing such medium-chain fatty acid and/or triglyceride containing a medium-chain fatty acid. For example, Patent Literature 5 proposes a method for producing a dairy beverage by dissolving a lignan compound in a medium-chain fatty acid triglyceride, and adding this solution to soy milk. The invention has been made in order to develop a useful beverage for sufficiently taking lignan compounds, and the medium-chain fatty acid triglyceride is added merely as a solvent to solve the lignan. Moreover, the influence of the medium-chain fatty acid triglyceride on a sensory evaluation of the soy milk is not mentioned at all. Hence, it has not been known at all that medium-chain fatty acid triglycerides suppress soybean odor, raw smell, astringency, and so forth of soy milk.